/*
 * Copyright 2010-2020 Alfresco Software, Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.engine.impl.bpmn.behavior;

import java.util.List;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.DynamicBpmnConstants;
import org.activiti.engine.delegate.BpmnError;
import org.activiti.engine.delegate.DelegateExecution;
import org.activiti.engine.delegate.Expression;
import org.activiti.engine.delegate.JavaDelegate;
import org.activiti.engine.impl.bpmn.helper.DelegateExpressionUtil;
import org.activiti.engine.impl.bpmn.helper.ErrorPropagation;
import org.activiti.engine.impl.bpmn.helper.SkipExpressionUtil;
import org.activiti.engine.impl.bpmn.parser.FieldDeclaration;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.delegate.ActivityBehavior;
import org.activiti.engine.impl.delegate.ActivityBehaviorInvocation;
import org.activiti.engine.impl.delegate.TriggerableActivityBehavior;
import org.activiti.engine.impl.delegate.invocation.JavaDelegateInvocation;
import org.apache.commons.lang3.StringUtils;

import com.fasterxml.jackson.databind.node.ObjectNode;

/**
 * {@link ActivityBehavior} used when 'delegateExpression' is used for a
 * serviceTask.
 *
 */
public class ServiceTaskDelegateExpressionActivityBehavior extends TaskActivityBehavior {

	private static final long serialVersionUID = 1L;

	protected String serviceTaskId;
	protected Expression expression;
	protected Expression skipExpression;
	private final List<FieldDeclaration> fieldDeclarations;

	public ServiceTaskDelegateExpressionActivityBehavior(String serviceTaskId, Expression expression, Expression skipExpression, List<FieldDeclaration> fieldDeclarations) {
		this.serviceTaskId = serviceTaskId;
		this.expression = expression;
		this.skipExpression = skipExpression;
		this.fieldDeclarations = fieldDeclarations;
	}

	@Override
	public void trigger(DelegateExecution execution, String signalName, Object signalData) {
		Object delegate = DelegateExpressionUtil.resolveDelegateExpression(expression, execution, fieldDeclarations);
		if (delegate instanceof TriggerableActivityBehavior) {
			((TriggerableActivityBehavior) delegate).trigger(execution, signalName, signalData);
		}
	}

	public void execute(DelegateExecution execution) {
		try {
			boolean isSkipExpressionEnabled = SkipExpressionUtil.isSkipExpressionEnabled(execution, skipExpression);
			if (!isSkipExpressionEnabled
					|| (isSkipExpressionEnabled && !SkipExpressionUtil.shouldSkipFlowElement(execution, skipExpression))) {

				if (Context.getProcessEngineConfiguration().isEnableProcessDefinitionInfoCache()) {
					ObjectNode taskElementProperties = Context.getBpmnOverrideElementProperties(serviceTaskId, execution.getProcessDefinitionId());
					if (taskElementProperties != null
							&& taskElementProperties.has(DynamicBpmnConstants.SERVICE_TASK_DELEGATE_EXPRESSION)) {
						String overrideExpression = taskElementProperties.get(DynamicBpmnConstants.SERVICE_TASK_DELEGATE_EXPRESSION).asText();
						if (StringUtils.isNotEmpty(overrideExpression)
								&& !overrideExpression.equals(expression.getExpressionText())) {
							expression = Context
									.getProcessEngineConfiguration()
									.getExpressionManager()
									.createExpression(overrideExpression);
						}
					}
				}

				Object delegate = DelegateExpressionUtil.resolveDelegateExpression(expression, execution, fieldDeclarations);
				if (delegate instanceof ActivityBehavior) {

					if (delegate instanceof AbstractBpmnActivityBehavior) {
						((AbstractBpmnActivityBehavior) delegate).setMultiInstanceActivityBehavior(getMultiInstanceActivityBehavior());
					}

					Context.getProcessEngineConfiguration()
							.getDelegateInterceptor()
							.handleInvocation(new ActivityBehaviorInvocation((ActivityBehavior) delegate, execution));

				} else if (delegate instanceof JavaDelegate) {
					Context.getProcessEngineConfiguration()
							.getDelegateInterceptor()
							.handleInvocation(new JavaDelegateInvocation((JavaDelegate) delegate, execution));
					leave(execution);

				} else {
					throw new ActivitiIllegalArgumentException("Delegate expression " + expression + " did neither resolve to an implementation of " + ActivityBehavior.class + " nor " + JavaDelegate.class);
				}
			} else {
				leave(execution);
			}
		} catch (Exception exc) {

			Throwable cause = exc;
			BpmnError error = null;
			while (cause != null) {
				if (cause instanceof BpmnError) {
					error = (BpmnError) cause;
					break;
				}
				cause = cause.getCause();
			}

			if (error != null) {
				ErrorPropagation.propagateError(error, execution);
			} else {
				throw new ActivitiException(exc.getMessage(), exc);
			}

		}
	}

}
